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From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH 05/17] writeback: quit throttling when signal pending
Cc: kosaki.motohiro@jp.fujitsu.com, Neil Brown <neilb@suse.de>,
        linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Mel Gorman <mel@csn.ul.ie>, Rik van Riel <riel@redhat.com>,
        Chris Mason <chris.mason@oracle.com>, Christoph Hellwig <hch@lst.de>,
        "Li, Shaohua" <shaohua.li@intel.com>
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> > > However, I suspect the process is guaranteed to exit on
> > > fatal_signal_pending, so it won't dirty more pages :)
> > 
> > Process exiting is delayed until syscall exiting. So, we exit write syscall
> > manually if necessary.
> 
> Got it, you mean this fix. It looks good. I didn't add "status =
> -EINTR" in the patch because the bottom line "written ? : status" will
> always select the non-zero written.
> 
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 3d4df44..f6d2740 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2304,7 +2304,8 @@ again:
>  		written += copied;
>  
>  		balance_dirty_pages_ratelimited(mapping);
> -
> +		if (fatal_signal_pending(current))
> +			break;
>  	} while (iov_iter_count(i));

Looks good. however other callers also need to be updated.